Hybrid energy systems typically include an engine having its prime mover, e.g., a crankshaft, mechanically decoupled from one or more loads, e.g., traction and/or non-traction loads. Hybrid energy systems usually also include an energy storage device configured to store energy received from either the engine during an engine overpowering mode or from the loads during an energy regenerating mode. The engine and storage device are electrically coupled to the loads via a motor-generator to allow the engine to also operate as an energy source rather than a conventional drive mechanism and allowing the storage device to recover regenerated energy. The amount and frequency of operated-requested and regenerated energy with respect to the loads are usually independent of the amount of energy stored within the storage device. Often, regenerated energy is wasted as heat because the storage device can only accept a portion of the regenerated energy. Additionally, the engine output is often increased to satisfy energy demands from the loads because the storage device can only output a portion of the demanded energy. Furthermore, operator-requested energy may periodically exceed the maximum energy output of the engine and storage device.
U.S. Pat. No. 5,832,396 (“the '396 patent”) issued to Moroto et al. discloses a hybrid vehicle having a hybrid energy system including a battery and a method for charging the battery. The method of the '396 patent includes inputting a destination and determining a route that the vehicle may take. The method also includes determining the current residual charge of the battery and makes a schedule for a target value of the residual charge in the battery based on the driving route, present location of the vehicle, and road conditions. The schedule is based on the necessary driving output estimated from the route information, such as altitude or road type. If the vehicle is being driven on the determined route, a controller controls the current residual charge of the battery to match the scheduled residual charge of the battery at a given location on the determined route by adjusting the output of a motor and/or engine. If the determined route includes an initial uphill slope and a subsequent downhill slope, the engine may be operated to increase the residual charge of the battery to be approximately 100% before driving uphill and the residual charge of the battery may not be immediately replenished because the battery will be later charged when driving downhill.
Because the method of the '396 patent adjusts the residual charge of the battery based on road conditions, the controller includes a memory for storing map data for the driving route. Although map data may be readily available for on-road applications, e.g., permanent highways, it may not be readily available for off-road applications, e.g., temporary construction sites. Additionally, the method of the '396 patent may charge and discharge the battery based on changing traction loads, energy demands, and regeneration, however, it may not account for changing non-traction loads.
The present disclosure is directed to overcoming one or more of the shortcomings set forth above.